Green Sea Turtle

Photograph by Tim Laman

Green sea turtles are reptiles whose ancestors evolved on land and took to the sea to live about 150 million years ago. They are one of the few species so ancient that they watched the dinosaurs evolve and become extinct.

Loggerhead Turtle

Photograph by Joel Sartore, National Geographic

Loggerhead turtles are the most abundant of all the marine turtle species in U.S. waters. But persistent population declines due to pollution, shrimp trawling, and development in their nesting areas, among other factors, have kept this wide-ranging seagoer on the threatened species list since 1978.

Leatherback Turtle Laying Eggs

Olive Ridley Sea Turtle

Photograph by Bill Curtsinger

Olive ridleys get their name from the coloring of their heart-shaped shell, which starts out grey but becomes olive green once the turtles are adults. They have one to two visible claws on each of their paddle-like flippers.

Flatback Turtle

Photograph by Jason Edwards, National Geographic

Flatback turtles, such as this one in the Melbourne Aquarium, are native to Australia. Their carapaces can reach up to 39 inches (99 centimeters) long.